1. Field of the Invention
The field of the invention is that of aircraft instrument panel viewing devices. The invention can however apply to other industrial fields comprising centralized control stations comprising an assembly of viewing devices and requiring fast reconfiguration in the event of a fault.
2. Description of the Prior Art
An aircraft viewing system demands great availability. This system comprises several viewing devices arranged on the instrument panel and various computers linked to the avionics system of the craft. This assembly is complex and manipulates thousands of aeronautical parameters. Moreover, it is programmed to reconfigure itself automatically or manually according to circumstances, thus adding to the complexity of the system.
Experience shows that the avionics system may be prone to errors causing the momentary loss of the information displayed on the viewing facilities and involving the application of complex procedures by the crew and significant extra work. Even if the probability of these faults is very low, less than 105 per flight hour, the mean duration of this loss of information is of the order of 40 seconds, which, for an aircraft in flight, is a considerable duration.
Analysis of these faults shows that the great majority of these errors are due to failures of the software. Faults involving the hardware occur in more exceptional circumstances. Software faults reveal operational limits that were not discovered during the test phases, despite robustness tests.
To remedy these faults, the existing solutions consist in causing a fatal fault after detection of the irrecoverable error by the software.
For example, within the framework of the interface standardized according to the ARINC 653 aeronautical standard, this consists in declaring a “reset module” which causes the complete initialization of the hardware module and restarts a power-up test so as to ensure that the module can guarantee the integrity of the system. This procedure can take, as has been stated, up to forty seconds before the pilot regains an operational image on his viewing facility or facilities.
As has been seen, in most faults, the hardware is not at issue and this restart associated with a complete test of the system is not necessary.